There is known a seat which includes an air cell, which can be expanded and contracted by supplied/exhausted air, therein, and is configured such that a hardness, a shape, or the like can be adjusted by expanding and contracting the air cell (for example, see Patent Document 1).
In the seat described in Patent Document 1, the air cell is attached in a resin plate, and is supported from a seat back surface side by the resin plate. The resin plate is attached in a seat frame through a plurality of wires laid across the seat frame. The seat front surface side of the air cell is covered with a cushion pad made of relatively soft urethane foam and the like.